Soaring, based on your "not talking to each other" comment you're saying some alternators only work with mechanical VRs and some only work with electronic VRs? How do you know what kind of alternator you have?

 

I'm not real positive about the electrical current compatibility of various alternators and Voltage regulators. I just know that when my original alternator went out, I was given strong advice by a very knowledgable mechanic friend of mine that the mechanical voltage regulator would not work as well as a new electronic voltage regular. There is a compatibility issue here, and maybe some smarter members here can give you an electrical engineering answer. But, just as a rule of the thumb, whenever you replace the alternator, also replace the voltage regulator unless you already have an electonic VR in it to begin with.